> On Wed, 17 Jan 2007 11:43:42 -0800 (PST) Christoph Lameter <[EMAIL > PROTECTED]> wrote: > On Tue, 16 Jan 2007, Andrew Morton wrote: > > > Do what blockdevs do: limit the number of in-flight requests (Peter's > > recent patch seems to be doing that for us) (perhaps only when PF_MEMALLOC > > is in effect, to keep Trond happy) and implement a mempool for the NFS > > request critical store. Additionally: > > > > - we might need to twiddle the NFS gfp_flags so it doesn't call the > > oom-killer on failure: just return NULL. > > > > - consider going off-cpuset for critical allocations. It's better than > > going oom. A suitable implementation might be to ignore the caller's > > cpuset if PF_MEMALLOC. Maybe put a WARN_ON_ONCE in there: we prefer that > > it not happen and we want to know when it does. > > Given the intermediate layers (network, additional gizmos (ip over xxx) > and the network cards) that will not be easy.
Paul has observed that it's already done. But it seems to not be working. > > btw, regarding the per-address_space node mask: I think we should free it > > when the inode is clean (!mapping_tagged(PAGECACHE_TAG_DIRTY)). Chances > > are, the inode will be dirty for 30 seconds and in-core for hours. We > > might as well steal its nodemask storage and give it to the next file which > > gets written to. A suitable place to do all this is in > > __mark_inode_dirty(I_DIRTY_PAGES), using inode_lock to protect > > address_space.dirty_page_nodemask. > > The inode lock is not taken when the page is dirtied. The inode_lock is taken when the address_space's first page is dirtied. It is also taken when the address_space's last dirty page is cleaned. So the place where the inode is added to and removed from sb->s_dirty is, I think, exactly the place where we want to attach and detach address_space.dirty_page_nodemask. > The tree_lock > is already taken when the mapping is dirtied and so I used that to > avoid races adding and removing pointers to nodemasks from the address > space. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/